USB device

ABSTRACT

According to one embodiment, a USB device includes a USB connector, a casing, and a holding member. The casing is provided with an opening. The holding member includes a holder, a support, and a first extension. The holder holds the USB connector. The support extends from the holder. The first extension has a protrusion, extends from the support, and is bendable. The protrusion is housed in the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2017-059931, filed on Mar. 24, 2017, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a USB device.

BACKGROUND

A USB device having a USB connector includes a casing for housing asubstrate and a terminal for mounting the USB connector.

When the USB connector and the casing are pulled away from each other,the casing may be detached from the USB connector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a USB memory according to afirst embodiment;

FIG. 2 is an exploded, perspective view of the USB memory according tothe first embodiment;

FIG. 3 is a sectional view of the USB memory according to the firstembodiment;

FIG. 4 is a sectional view of the USB memory according to the firstembodiment along a line F4-F4 in FIG. 3;

FIG. 5 is an enlarged sectional view of a part of the USB memoryaccording to the first embodiment;

FIG. 6 is a plan view of the USB memory without an outer casingaccording to the first embodiment;

FIG. 7 is a side view of a part of the USB memory without the outercasing according to the first embodiment;

FIG. 8 is a block diagram illustrating an example of a configuration ofthe USB memory according to the first embodiment; and

FIG. 9 is a plan view of a USB memory without an outer casing accordingto a second embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a USB device includes a USBconnector, a casing, and a holding member. The casing is provided with aport that opens in a first direction, and has a first inner face that isprovided with an opening, faces a direction intersecting with the firstdirection, and faces the port. The holding member includes a holder, asupport, and a first extension. The holder is at least partially housedin the port, includes an end outside the port, and is provided with aninsertion port that opens in the end, and the holder holds the USBconnector while the USB connector projects outward through the insertionport. The support extends from the holder inside the port. The firstextension includes a first face facing the first inner face and aprotrusion on the first face, and extends inside the port from thesupport along the first inner face in a direction toward the end or in adirection orthogonal to the first direction. The first extension isbendable. The protrusion is housed in the opening.

First Embodiment

A first embodiment is described below with reference to FIG. 1 to FIG.8. In the present specification, constituent elements according toembodiments may be represented differently and described differently.The constituent elements and descriptions thereof may be expresseddifferently from those described herein. Further, constituent elementsgiven no different expressions and descriptions thereof may also beexpressed differently.

FIG. 1 is a perspective view illustrating a USB flash drive(hereinafter, USB memory) 10 according to a first embodiment. FIG. 2 isan exploded, perspective view of the USB memory 10 according to thefirst embodiment.

The USB memory 10 is an example of a USB device, and can be referred toas, for example, electronic device, semiconductor memory device,semiconductor device, storage device, secondary storage device,removable medium, or device. The USB device may be, for example, atablet, a smartphone, a mobile phone, an IC recorder, a householdelectric machine, a secondary storage device such as a hard disk drive(HDD) or a solid-state drive (SSD), a cable or an adaptor for connectinga device to another device, or other USB devices.

As illustrated in FIG. 1, the USB memory 10 according to the presentembodiment has, for example, a substantially rectangular parallelepipedshape. The USB memory 10 can have other shapes. As illustrated in thedrawings, an X-axis, a Y-axis, and a Z-axis are defined in thespecification. The X-axis, the Y-axis, and the Z-axis are orthogonal toeach other. The X-axis is laid along the width of the USB memory 10. TheY-axis is laid along the length of the USB memory 10. The Z-axis is laidalong the thickness of the USB memory 10.

As illustrated in FIG. 1 and FIG. 2, the USB memory 10 includes a case11, a substrate 12, two flash memories 13, a controller 14, and a USBconnector 15. The flash memories 13 can be also referred to as, forexample, non-volatile memories, memories, storages, or electroniccomponents. The controller 14 is an example of an electronic componentand can be referred to as control unit, for example. The USB connector15 can be referred to as, for example, plug, connection terminal,insertion, or connection.

The case 11 houses therein the substrate 12, the flash memories 13, thecontroller 14, and a part of the USB connector 15. The USB connector 15projects from the case 11, and can be covered with, for example, a lidor a cap attachable to the case 11. The case 11 is made from, forexample, synthetic resin. The case 11 can be made from other materials.

The substrate 12 is, for example, a printed circuit board (PCB). Thesubstrate 12 can be another substrate such as a flexible printed circuitboard (FPC). The substrate 12 is substantially quadrangular(rectangular) plate-like expanding on an X-Y plane. The substrate 12 canhave other shapes.

FIG. 3 is a sectional view of the USB memory 10 according to the firstembodiment. As illustrated in FIG. 3, the substrate 12 has a firstmounting face 21 and a second mounting face 22. The first mounting face21 is an example of a second face. The second mounting face 22 is anexample of a third face.

The first mounting face 21 is substantially flat face facing a positiveZ-axis direction (a positive direction of the Z-axis, a directionindicated by the arrow of the Z-axis). The second mounting face 22 issubstantially flat face facing a negative Z-axis direction (a negativedirection of the Z-axis, an opposite direction of the arrow of theZ-axis). The second mounting face 22 is opposite to the first mountingface 21.

FIG. 4 is a sectional view of the USB memory 10 according to the firstembodiment along a line F4-F4 in FIG. 3. As illustrated in FIG. 4, thesubstrate 12 has a first edge 25, a second edge 26, a first side edge27, and a second side edge 28. The first edge 25 is an example of afirst end. The first edge 25, the second edge 26, the first side edge27, and the second side edge 28 connect an end of the first mountingface 21 and an end of the second mounting face 22.

The first edge 25 is an end of the substrate 12 facing a positive Y-axisdirection (a positive direction of the Y-axis, a direction indicated bythe arrow of the Y-axis), and extends in the X-axis direction. Thepositive Y-axis direction is an example of a first direction. The secondedge 26 is an end of the substrate 12 facing a negative Y-axis direction(a negative direction of the Y-axis, an opposite direction of the arrowof the Y-axis). The negative Y-axis direction is opposite to thepositive Y-axis direction, and is an example of a second direction. Thefirst edge 25 and the second edge 26 face in the Y-axis direction. TheY-axis direction includes the positive Y-axis direction and the negativeY-axis direction. The second edge 26 is away from the first edge 25 inthe negative Y-axis direction and extends in the X-axis direction.

The first side edge 27 is an end of the substrate 12 facing the positiveX-axis direction (a positive direction of the X-axis, a directionindicated by the arrow of the X-axis), and extends in the Y-axisdirection. The second side edge 28 is an end of the substrate 12 facingthe negative X-axis direction (a negative direction of the X-axis, anopposite direction of the arrow of the X-axis). The first side edge 27and the second side edge 28 face the X-axis direction. The X-axisdirection includes the positive X-axis direction and the negative X-axisdirection. The second side edge 28 is away from the first side edge 27in the negative X-axis direction and extends in the Y-axis direction.

The substrate 12 has a substantially rectangular shape extending in theY-axis direction in a plan view of the first mounting face 21. Adistance between the first edge 25 and the second edge 26 in the Y-axisdirection is longer than a distance between the first side edge 27 andthe second side edge 28 in the X-axis direction.

The first edge 25 and the second edge 26 are short sides of thesubstrate 12. The first side edge 27 and the second side edge 28 arelong sides of the substrate 12. The Y-axis direction can be referred toas a long side direction of the substrate 12. The X-axis direction canbe referred to as a short side direction of the substrate 12.

As illustrated in FIG. 3, the two flash memories 13 are mounted on thefirst mounting face 21 and the second mounting face 22 of the substrate12. For example, the flash memories 13 are each provided with terminalswhich are electrically connected to electrodes on the first mountingface 21 and the second mounting face 22 by soldering. The flash memories13 can be mounted on either of the first mounting face 21 and the secondmounting face 22.

The flash memories 13 are NAND flash memories, for example. The USBmemory 10 is not limited to a NAND flash memory, and may include othernonvolatile memories such as a NOR flash memory, a MagnetoresistiveRandom Access Memory (MRAM), a Phase-change Random Access Memory (PRAM),a Resistive Random Access Memory (ReRAM), and a Ferroelectric RandomAccess Memory (FeRAM).

The controller 14 is mounted on the first mounting face 21 of thesubstrate 12. For example, the controller 14 is provided with terminalswhich are electrically connected to the electrodes on the first mountingface 21 by soldering. The controller 14 can be mounted on the secondmounting face 22. The controller 14 controls the flash memories 13 tocontrol communication between the USB memory 10 and a host device, forexample. The controller 14 is located between the flash memories 13 andthe first edge 25 of the substrate 12 in the Y-axis direction.

The USB connector 15 is, for example, a male connector (a plug)conforming to the USB 3.1 Type-A standard or the USB 3.0 Type-Astandard. The USB connector 15 has a substantially rectangularparallelepiped shape extending substantially in the Y-axis direction.The USB connector 15 includes an insertion 31 and a mount 32.

The insertion 31 has a substantially rectangular parallelepiped shapeextending substantially in the Y-axis direction. The insertion 31 has afirst end 31 a and a second end 31 b. The second end 31 b is an exampleof a second end. The first end 31 a is an end of the insertion 31 in thepositive Y-axis direction. The second end 31 b is an end (edge) of theinsertion 31 in the negative Y-axis direction, and is opposite the firstend 31 a. The second end 31 b faces the first edge 25 of the substrate12.

FIG. 5 is an enlarged sectional view illustrating a part of the USBmemory 10 according to the first embodiment. As illustrated in FIG. 5,the insertion 31 includes a connection port 31 c and connectionterminals 31 d. The connection port 31 c is an opening in the first end31 a. The connection terminals 31 d are electrodes located inside theconnection port 31 c. The insertion 31 includes, for example, eightconnection terminals 31 d. The insertion 31 of the USB connector 15conforming to the USB 2.0 standard includes four connection terminals 31d. The number of the connection terminals 31 d is not limited to theseexamples.

The insertion 31 is inserted into, for example, a USB connector (afemale connector or a socket) of the host device. A connection terminalof the socket is inserted into the connection port 31 c, andelectrically connected to the connection terminals 31 d. Thus, the USBmemory 10 and the host device are electrically connected to each other.

The mount 32 extends from the second end 31 b of the insertion 31 in thenegative Y-axis direction. The mount 32 covers a part of the secondmounting face 22 of the substrate 12. The mount 32 has a tip end 32 a.The tip end 32 a is an example of a third end.

The tip end 32 a is an end of the mount 32 opposite the insertion 31.The tip end 32 a is an end (edge) of the USB connector 15 in thenegative Y-axis direction. The first end 31 a of the insertion 31 is anend (edge) of the USB connector 15 in the positive Y-axis direction.

The mount 32 includes mounting pins 32 b. The mounting pins 32 b areconnected to the connection terminals 31 d. The mounting pins 32 b areelectrically connected to the electrodes on the second mounting face 22by soldering. That is, the USB connector 15 is mounted on the secondmounting face 22 of the substrate 12. The USB connector 15 can bemounted on the first mounting face 21.

In the Z-axis direction, the length (thickness) of the USB connector 15is longer than the length (thickness) of the substrate 12. Thus, whenthe USB connector 15 is mounted on the second mounting face 22, a partof the insertion 31 projects from the first mounting face 21 of thesubstrate 12 in the positive Z-axis direction.

As illustrated in FIG. 2, the case 11 includes an inner casing 41 and anouter casing 42. The inner casing 41 is an example of a holding member.The outer casing 42 is an example of a casing. The inner casing 41 holdsthe USB connector 15 in the outer casing 42.

As illustrated in FIG. 5, the inner casing 41 includes a holder 51, afirst wall 52, a first spring 53, a second wall 55, and a second spring56. The first wall 52 is an example of a support. The first spring 53 isan example of a first extension. The second spring 56 is an example of asecond extension.

The holder 51 has a substantially quadrangular, tubular (frame) shape.The holder 51 includes an outer end 51 a, an inner end 51 b, an innerperiphery 51 c, and an outer periphery 51 d. The outer end 51 a is anexample of an end. The outer end 51 a is an end of the holder 51 in thepositive Y-axis direction. The inner end 51 b is an end of the holder 51in the negative Y-axis direction.

The inner periphery 51 c and the outer periphery 51 d connect the outerend 51 a and the inner end 51 b to each other. The inner periphery 51 cfaces the inside of the tubular holder 51. The outer periphery 51 d isopposite the inner periphery 51 c, facing the outside of the tubularholder 51.

The holder 51 is provided with an insertion port 61. The insertion port61 penetrates through the holder 51 in the Y-axis direction and opens tothe outer end 51 a and the inner end 51 b. The insertion port 61 is asubstantially quadrangular hole having substantially the same shape asthe insertion 31 of the USB connector 15. The shape of the insertionport 61 is not limited thereto.

The insertion 31 of the USB connector 15 projects outside from the case11 through the insertion port 61. The inner periphery 51 c of the holder51 contacts with the insertion 31, thereby restricting the movement ofthe USB connector 15 with respect to the inner casing 41 in the X-axisdirection and in the Z-axis direction. That is, the inner casing 41holds the USB connector 15 while the USB connector 15 projects outsidethrough the insertion port 61.

Further, as illustrated in FIG. 4, the inner end 51 b of the holder 51contacts with the first edge 25 of the substrate 12, thereby restrictingthe movement of the substrate 12 with respect to the inner casing 41 inthe positive Y-axis direction. Thus, the inner end 51 b of the holder 51restricts the movement of the USB connector 15 on the substrate 12 withrespect to the inner casing 41 in the positive Y-axis direction.

As illustrated in FIG. 5, the holder 51 is provided with depressions 62in the outer periphery 51 d. For example, tabs of the lid are fittedinto the depressions 62. Thereby, the lid is detachably attached to thecase 11.

The first wall 52 extends from the inner end 51 b of the holder 51 inthe negative Y-axis direction. The first wall 52 is substantiallyquadrangular plate-like expanding on the X-Y plane. The shape of thefirst wall 52 is not limited thereto. The first mounting face 21 of thesubstrate 12 opposes the first wall 52 with a gap.

FIG. 6 is a plan view of the USB memory 10 without the outer casing 42according to the first embodiment. As illustrated in FIG. 6, the firstwall 52 is provided with a first pass-through slot 52 a. The firstpass-through slot 52 a penetrates through the first wall 52 in theZ-axis direction. The first spring 53 is located inside the firstpass-through slot 52 a, and extends from an inner end 52 b of the firstwall 52, the inner end 52 b defining the first pass-through slot 52 a.

The first spring 53 is substantially quadrangular plate-like expandingon the X-Y plane. The shape of the first spring 53 is not limitedthereto. The first spring 53 has a surface 53 a. The surface 53 a is anexample of a first face. The surface 53 a is substantially flat facefacing the positive Z-axis direction. The surface 53 a faces oppositelyto the substrate 12 and the USB connector 15.

The first spring 53 extends from the first wall 52 in the positiveY-axis direction. The first spring 53 extends toward the holder 51 in aplan view in the negative Z-axis direction. The negative Z-axisdirection is oriented to the surface 53 a. The direction toward theholder 51 is not limited to the positive Y-axis direction, and may be adiagonal direction including the positive Z-axis direction, such as anupper right direction or an upper left direction in FIG. 6, for example.

The first spring 53 is resiliently bendable around a connection 65between the first wall 52 and the first spring 53 as a fulcrum (anaxis). That is, the first spring 53 can be resiliently bent in acantilever form at the connection 65 as a fixed end toward or away fromthe substrate 12.

The first spring 53 further includes a protrusion 66. The protrusion 66is provided on the surface 53 a of the first spring 53 and projects inthe positive Z-axis direction. The protrusion 66 has a substantiallyrectangular parallelepiped shape. The protrusion 66 can have othershapes. The protrusion 66 has a first contact face 66 a and a secondcontact face 66 b.

The first contact face 66 a is substantially flat face facing thepositive Y-axis direction. The second contact face 66 b is opposite thefirst contact face 66 a and is substantially flat face facing thenegative Y-axis direction. The second contact face 66 b can be aninclined face, extending away from the surface 53 a as extending in thepositive Y-axis direction.

The protrusion 66 is located away from a front end 53 b of the firstspring 53 in the negative Y-axis direction. The front end 53 b is an endof the first spring 53 opposite the connection 65. In other words, thefront end 53 b is a front end of the extending first spring 53 in adirection in which the first spring portion 53 extends. That is, a partof the surface 53 a is located between the protrusion 66 and the frontend 53 b.

As illustrated in FIG. 5, in the positive Y-axis direction, the frontend 53 b of the first spring 53 is located between the controller 14 andthe second end 31 b of the insertion 31 of the USB connector 15. Theposition of the front end 53 b is not limited thereto.

The second wall 55 extends from the inner end 51 b of the holder 51 inthe negative Y-axis direction. The second wall 55 is substantiallyquadrangular plate-like expanding on the X-Y plane. The shape of thesecond wall 55 is not limited thereto. The second mounting face 22 ofthe substrate 12 opposes the second wall 55 with a gap.

The second wall 55 is provided with a second pass-through slot 55 a. Thesecond pass-through slot 55 a penetrates through the second wall 55 inthe Z-axis direction. The second spring 56 is located inside the secondpass-through slot 55 a, and extends from the inner end 51 b of theholder 51 in the negative Y-axis direction.

The second spring 56 is substantially quadrangular plate-like expandingon the X-Y plane. The shape of the second spring 56 is not limitedthereto. The second spring 56 has an inner face 56 a and an outer face56 b.

The inner face 56 a is substantially flat face facing the positiveZ-axis direction. The inner face 56 a opposes the substrate 12 with agap. The inner face 56 a faces the mount 32 of the USB connector 15. Theouter face 56 b is opposite the inner face 56 a and is substantiallyflat face facing the negative Z-axis direction.

The second spring 56 is resiliently bendable around a connection 67between the holder 51 and the second spring 56 as a fulcrum (an axis).That is, the second spring 56 can be resiliently bent in a cantileverform at the connection 67 being a fixed end toward or away from thesubstrate 12.

The second spring 56 further includes a tab 68 and ribs 69. The tab 68is provided on the inner face 56 a of the second spring 56, and projectsin the Z-axis positive direction. The tab 68 is hooked by the tip end 32a of the mount 32 of the USB connector 15. In other words, the tab 68faces the tip end 32 a. The tab 68 comes into contact with the tip end32 a, thereby restricting the movement of the USB connector 15 withrespect to the inner casing 41 in the negative Y-axis direction.

The ribs 69 are provided on the outer face 56 b of the second spring 56.The ribs 69 extend in the Y-axis direction. The ribs 69 reinforce thesecond spring 56, and prevent the second spring 56 from being damagedwhen the tab 68 is pressed by the tip end 32 a of the mount 32 in thenegative Y-axis direction.

FIG. 7 is a side view of a part of the USB memory 10 without the outercasing 42 according to the first embodiment. As illustrated in FIG. 7,the inner casing 41 further includes first sidewalls 71, secondsidewalls 72, and protrusions 73.

The inner casing 41 includes the two first sidewalls 71 extending in thenegative Z-axis direction from both X-axial ends of the first wall 52.The first sidewalls 71 each have a first end face 71 a. The first endface 71 a is an example of a first restrictor. The first end face 71 ais an end of the first sidewall 71 in the negative Z-axis direction.

The inner casing 41 has the two second sidewalls 72 extending in thepositive Z-axis direction from both X-axial ends of the second wall 55.The second sidewalls 72 each have a second end face 72 a. The second endface 72 a is an example of a second restrictor. The second end face 72 ais an end of the second sidewall 72 in the positive Z-axis direction.

The first end face 71 a at least partially faces the first mounting face21 of the substrate 12. The first end face 71 a comes into contact withthe first mounting face 21, thereby restricting the movement of thesubstrate 12 with respect to the inner casing 41 in the positive Z-axisdirection.

The second end face 72 a at least partially faces the second mountingface 22 of the substrate 12. The second end face 72 a comes into contactwith the second mounting face 22, thereby restricting the movement ofthe substrate 12 with respect to the inner casing 41 in the negativeZ-axis direction.

The inner casing 41 is provided with the two protrusions 73 that extendin the negative Y-axis direction from both X-axial ends of the inner end51 b of the holder 51. The protrusions 73 connect the first sidewalls 71and the second sidewalls 72. The protrusions 73 project from the firstand second sidewalls 71 and 72 oppositely (outward) to the substrate 12in the X-axis direction.

The protrusions 73 are substantially rectangular parallelepipedplate-like expanding on a Y-Z plane, and each have a first side end face73 a, a second side end face 73 b, and a third side end face 73 c. Thefirst side end face 73 a is an example of a fourth restrictor.

The first side end face 73 a is substantially flat face facing thenegative Y-axis direction. The second side end face 73 b issubstantially flat face facing the positive Z-axis direction. The thirdside end face 73 c is opposite the second side end face 73 b and issubstantially flat face facing the negative Z-axis direction.

As illustrated in FIG. 2, the outer casing 42 has a cylindrical shapewith a closed end, extending in the Y-axis direction. The outer casing42 can have other shapes. The outer casing 42 has an open end 81 and aclosed end 82.

The open end 81 faces in the positive Y-axis direction. The closed end82 is opposite the open end 81 and faces in the negative Y-axisdirection. The outer casing 42 is provided with a port 84 in the openend 81. That is, the port 84 opens in the positive Y-axis direction.

The port 84 is a hole (a hollow) with a bottom, extending from the openend 81 in the negative Y-axis direction. The port 84 may be athrough-hole also open in the closed end 82. The port 84 accommodates apart of the inner casing 41, the substrate 12, the flash memories 13,the controller 14, and the mount 32 of the USB connector 15. Thus, thetip end 32 a of the mount 32 is located inside the port 84.

As illustrated in FIG. 5, a part of the holder 51 of the inner casing 41is located outside the port 84. The outer end 51 a, a part of the outerperiphery 51 d, and the depressions 62 in the holder 51 are locatedoutside the port 84. Meanwhile, the first wall 52, the first spring 53,the second wall 55, the second spring 56, the tab 68, the firstsidewalls 71, the second sidewalls 72, and the protrusions 73 arelocated inside the port 84.

As illustrated in FIG. 4 and FIG. 5, the outer casing 42 has an innerperiphery 85 that faces the port 84 to define the port 84. The innerperiphery 85 includes a first inner face 85 a, a second inner face 85 b,a third inner face 85 c, and a fourth inner face 85 d. The first tofourth inner faces 85 a, 85 b, 85 c, and 85 d face the port 84 to definea part of the port 84.

The first inner face 85 a is substantially flat face facing the negativeZ-axis direction. The negative Z-axis direction is an example of adirection intersecting with the first direction. The second inner face85 b is substantially flat face facing the positive Z-axis direction.The second inner face 85 b opposes the first inner face 85 a with a gapin the Z-axis direction.

The third inner face 85 c is substantially flat face facing the negativeX-axis direction. The fourth inner face 85 d is substantially flat facefacing the positive X-axis direction. The fourth inner face 85 d opposesthe third inner face 85 c with a gap in the X-axis direction.

As illustrated in FIG. 5, the first inner face 85 a faces a part of theouter periphery 51 d of the holder 51, the first wall 52, and thesurface 53 a of the first spring 53. That is, the first inner face 85 aand the surface 53 a of the first spring 53 oppose each other. The firstinner face 85 a, the part of the outer periphery 51 d of the holder 51,the first wall 52, and the surface 53 a of the first spring 53 cancontact with each other or can be slightly away from each other.

The first mounting face 21 of the substrate 12 faces the first innerface 85 a. In the Z-axis direction, a distance between the first innerface 85 a and the first mounting face 21 is longer than a distancebetween the first end face 71 a of the first sidewall 71 and the firstmounting face 21. Thus, the first end face 71 a is closer to the firstmounting face 21 than the first inner face 85 a, facing the firstmounting face 21.

The second inner face 85 b faces a part of the outer periphery 51 d ofthe holder 51, the second wall 55, and the ribs 69 of the second spring56. The second inner face 85 b and the outer face 56 b of the secondspring 56 oppose each other. The second inner face 85 b, a part of theouter periphery 51 d of the holder 51, the second wall 55, and the ribs69 can contact with each other or can be slightly away from each other.

The second inner face 85 b faces the second mounting face 22 of thesubstrate 12. In the Z-axis direction, a distance between the secondinner face 85 b and the second mounting face 22 is longer than adistance between the second end face 72 a of the second sidewall 72 andthe second mounting face 22. Thus, the second end face 72 a is closer tothe second mounting face 22 than the second inner face 85 b, facing thesecond mounting face 22.

The third inner face 85 c and the fourth inner face 85 d face a part ofthe outer periphery 51 d of the holder 51, the first sidewall 71, thesecond sidewall 72, and the protrusions 73. The third inner face 85 cand the fourth inner face 85 d, a part of the outer periphery 51 d ofthe holder 51, the first sidewall 71, the second sidewall 72, and theprotrusions 73 can contact with each other or can be slightly away fromeach other.

The first to fourth inner faces 85 a, 85 b, 85 c, and 85 d come intocontact with the outer periphery 51 d of the holder 51, therebyrestricting the movement of the inner casing 41 with respect to theouter casing 42 in the X-axis direction and the Z-axis direction.

The outer casing 42 is provided with an opening 86. The opening 86 is,for example, a through-hole, and opens in the first inner face 85 a. Theopening 86 can be a hole with a bottom that opens in the first innerface 85 a.

The opening 86 is larger than the protrusion 66. When a part of theinner casing 41 is housed in the port 84, the protrusion 66 enters theopening 86. In other words, the protrusion 66 is housed in the opening86. With the protrusion 66 housed in the opening 86, the surface 53 a ofthe first spring 53 extends along the first inner face 85 a. The surface53 a of the first spring 53 can contact with the first inner face 85 aor can be slightly away from the first inner face 85 a.

The outer casing 42 has a first receiving face 86 a and a secondreceiving face 86 b. The first receiving face 86 a and the secondreceiving face 86 b are inner faces of the opening 86. The firstreceiving face 86 a is substantially flat face facing the negativeY-axis direction. The second receiving face 86 b is substantially flatface facing the positive Y-axis direction and opposes the firstreceiving face 86 a.

With the protrusion 66 housed in the opening 86, the first receivingface 86 a opposes the first contact face 66 a of the protrusion 66. Thesecond receiving face 86 b opposes the second contact face 66 b of theprotrusion 66. The first receiving face 86 a and the second receivingface 86 b, and the first contact face 66 a and the second contact face66 b can contact with each other or can be slightly away from eachother.

When the protrusion 66 is housed in the opening 86, the first spring 53with the protrusion 66 restricts the inner casing 41 from moving withrespect to the outer casing 42 in the positive and negative Y-axisdirections. That is, the first contact face 66 a of the protrusion 66contacts with the first receiving face 86 a of the opening 86, therebyrestricting the inner casing 41 from moving in the positive Y-axisdirection with respect to the outer casing 42. Further, by the contactbetween the second contact face 66 b of the protrusion 66 and the secondreceiving face 86 b of the opening 86, the inner casing 41 is restrictedfrom moving in the negative Y-axis direction with respect to the outercasing 42.

As illustrated in FIG. 2 and FIG. 4, the third inner face 85 c and thefourth inner face 85 d are each provided with a recess 87. The recess 87is substantially quadrangular indentation. The recess 87 has a firstinternal face 87 a, a second internal face 87 b, and a third internalface 87 c. The first internal face 87 a is an example of a thirdrestrictor. The first to third internal faces 87 a, 87 b, and 87 c arelocated inside the port 84.

The first internal face 87 a is substantially flat face facing thepositive Y-axis direction. The second internal face 87 b issubstantially flat face facing the negative Z-axis direction. The thirdinternal face 87 c is substantially flat face facing the positive Z-axisdirection, and opposes the second internal face 87 b.

The protrusion 73 of the inner casing 41 is housed in the recess 87. Thefirst side end face 73 a of the protrusion 73 faces the first internalface 87 a. The second side end face 73 b faces the second internal face87 b. The third side end face 73 c faces the third internal face 87 c.

The first side end face 73 a comes into contact with the first internalface 87 a, thereby restricting the movement of the inner casing 41 withrespect to the outer casing 42 in the negative Y-axis direction, thatis, restricting the movement of the inner casing 41 toward the inside ofthe port 84 with respect to the outer casing 42.

The second side end face 73 b comes into contact with the secondinternal surface 87 b, thereby restricting the movement of the innercasing 41 with respect to the outer casing 42 in the positive Z-axisdirection. The third side end face 73 c comes into contact with thethird internal face 87 c, thereby restricting the movement of the innercasing 41 with respect to the outer casing 42 in the negative Z-axisdirection.

As illustrated in FIG. 6, the connection 65 between the first wall 52and the first spring 53 is located within an area in which theprotrusion 73 is provided in the Y-axis direction. Thus, the protrusion73 reinforces the inner casing 41 to protect the first wall 52 and thefirst spring 53 from being damaged by the first spring 53 when bentaround the connection 65.

FIG. 8 is a block diagram illustrating an exemplary configuration of theUSB memory 10 according to the first embodiment. As illustrated in FIG.8, the controller 14 controls transmission of data between the USBconnector 15 and the flash memory 13.

The controller 14 includes a USB interface (I/F) 14 a, an MPU 14 b, aROM 14 c, a RAM 14 d, a memory interface (I/F) 14 e, and an internal bus14 f. The USB I/F 14 a, the MPU 14 b, the ROM 14 c, the RAM 14 d, thememory I/F 14 e, and the internal bus 14 f are formed on, for example,one semiconductor substrate.

The USB I/F 14 a receives data and a command from a host device via theUSB connector 15. The data and the command are written in, for example,a Small Computer System Interface (SCSI) standard format. The USB I/F 14a receives data from the flash memory 13 and outputs the data in theSCSI standard format to the host device via the USB connector 15.

The MPU 14 b processes the command received from the host device and thedata received from the flash memory 13 using, for example, the ROM 14 cand the RAM 14 d. Further, the MPU 14 b performs authentication betweenthe host device and the USB memory 10 when the USB memory 10 isconnected to the host device.

The ROM 14 c holds data and programs for the processing by the MPU 14 b.The RAM 14 d functions as a work area for the processing by the MPU 14b. The RAM 14 d is, for example, a volatile semiconductor memory such asa DRAM.

The memory I/F 14 e is connected to the flash memory 13, for example,through wirings. The memory I/F 14 e transfers the command and the datafrom the USB I/F 14 a to the flash memory 13 and transfers the read datafrom the flash memory 13 to the USB I/F 14 a according to instructionsfrom the MPU 14 b.

The flash memory 13 receives a read command from the controller 14 toread data for output. The flash memory 13 receives a write command fromthe controller 14 to record the data.

When the USB connector 15 of the above USB memory 10 is extracted, forexample, from a socket of the host device, a tensile force Ft1,indicated by the arrow in FIG. 5, acts on the outer casing 42. Forexample, the tensile force Ft1 acts on the outer casing 42 when manuallypulled by a user.

When the outer casing 42 is pulled with the tensile force Ft1, a tensileforce (resistance) Ft2 acts on the USB connector 15 held in the socket.The tensile force Ft2 acting on the USB connector 15 also acts on theinner casing 41.

The tensile forces Ft1 and Ft2 cause the USB connector 15 and the innercasing 41 to move in the positive Y-axis direction with respect to theouter casing 42. In other words, the USB connector 15 and the innercasing 41 are to be pulled out from the port 84 of the outer casing 42.However, the first receiving face 86 a of the opening 86 comes intocontact with the first contact face 66 a of the protrusion 66 togenerate a pressing force Ft3 thereon.

As described above, the first spring 53 extends from the first wall 52in the positive Y-axis direction. In other words, the first spring 53extends from the first wall 52 in a direction toward the outer end 51 aof the holder 51 along the first inner face 85 a. The extended firstspring 53 is resiliently bendable around the connection 65 as a fulcrum.

The direction of the pressing force Ft3 is different from the directiontoward the connection 65. Thus, the pressing force Ft3 causes the firstspring 53 to rotate in a direction D1 around the connection 65 as afulcrum. That is, the pressing force Ft3 causes torque to act on thefirst spring 53.

The direction D1 is a direction in which the first spring 53 approachesthe first inner face 85 a of the port 84. Thus, the protrusion 66 is toenter the opening 86 further deeply. Also, the surface 53 a of the firstspring 53 is pressed onto the first inner face 85 a of the port 84.Because the first inner face 85 a receives the surface 53 a, deformationof the first spring 53 is prevented.

As described above, with the occurrence of the tensile forces Ft1 andFt2 that pull out the inner casing 41 from the port 84, the first spring53 is bent oppositely to the direction in which the protrusion 66 ispulled out from the opening 86. Thereby, the protrusion 66 is preventedfrom being pulled out from the opening 86, which restricts the innercasing 41 from moving with respect to the outer casing 42 in thepositive Y-axis direction.

Further, as described above, the inner end 51 b of the holder 51illustrated in FIG. 4 faces the first edge 25 of the substrate 12. Theinner end 51 b of the holder 51 comes into contact with the first edge25, thereby restricting the movement of the substrate 12 with respect tothe inner casing 41 in the positive Y-axis direction. This can restrictthe USB connector 15 on the substrate 12 from moving with respect to theinner casing 41 in the positive Y-axis direction.

Meanwhile, at the time of inserting the USB connector 15 of the USBmemory 10 into the socket, a pressing force Ft4, as illustrated by thearrow in FIG. 5, acts on the outer casing 42. For example, the pressingforce Ft4 acts on the outer casing 42 when pressed manually by a user.

When the outer casing 42 is pressed with the pressing force Ft4, apressing force (resistance) Ft5 acts on the USB connector 15 insertedinto the socket. The pressing force Ft5 acting on the USB connector 15also acts on the inner casing 41.

The pressing forces Ft4 and Ft5 cause the USB connector 15 and the innercasing 41 to move in the negative Y-axis direction with respect to theouter casing 42. In other words, the USB connector 15 and the innercasing 41 move toward the inside of the port 84 of the outer casing 42.Then, the first side end face 73 a of the protrusion 73 illustrated inFIG. 4 comes into contact with the first internal face 87 a of therecess 87.

As described above, by the contact between the first side end face 73 aand the first internal face 87 a, the inner casing 41 can be restrictedfrom moving with respect to the outer casing 42 in the negative Y-axisdirection, that is, from moving toward the inside of the port 84 of theouter casing 42.

As described above, the tab 68 illustrated in FIG. 5 contacts with thetip end 32 a of the USB connector 15, to restrict the movement of theUSB connector 15 with respect to the inner casing 41 in the negativeY-axis direction. Then, the pressing force Ft5 acts on the tab 68 viathe USB connector 15.

The second spring 56 is resiliently bendable around the connection 67 asa fulcrum. Because of this, the pressing force Ft5 causes the secondspring 56 to rotate in a direction D2 around the connection 67.

The direction D2 is a direction in which the second spring 56 approachesthe second inner face 85 b of the port 84. In other words, the directionD2 is a direction in which the tab 68 comes off from the tip end 32 a.However, in the positive Z-axis direction, the distance between thesecond spring 56 and the second inner face 85 b is shorter than thedistance between the tab 68 and the tip end 32 a of the mount 32 of theUSB connector 15 opposing each other. By contacting the second innerface 85 b at the ribs 69, the second spring 56 can be inhibited frombeing bent in the direction D2, maintaining the tab 68 in a hooked stateby the tip end 32 a.

In the USB memory 10 according to the first embodiment described above,the first spring 53 extends along the first inner face 85 a in adirection toward the outer end 51 a of the inner casing 41 from thefirst wall 52 of the inner casing 41 inside the port 84. When the innercasing 41 receives a pressing force to outside the port 84, the pressingforce Ft3 acts on the contact between the protrusion 66 and the opening86. The pressing force Ft3 causes the first spring 53 to bend in thedirection D1 toward the first inner face 85 a around the connection 65between the first wall 52 and the first spring 53 as a fulcrum. Thisprevents the protrusion 66 and the opening 86 from being disengaged,inhibiting the inner casing 41 from coming off from the outer casing 42.

The protrusion 66 is spaced apart from the front end 53 b of the firstspring 53 in the positive Y-axis direction. When the inner casing 41receives a pressing force to outside the port 84, the pressing force Ft3acts on the contact between the protrusion 66 and the opening 86. Thepressing force Ft3 causes the first spring 53 to bend in the directionD1 toward the first inner face 85 a around the connection 65 between thefirst wall 52 and the first spring 53 as a fulcrum. A part of thesurface 53 a is then pressed onto the first inner face 85 a, increasingthe friction force therebetween and inhibiting the first spring 53 frombending. Thus, the first spring 53 is prevented from being broken ordamaged and the inner casing 41 is prevented from coming off from theouter casing 42.

In the positive Y-axis direction, the front end 53 b of the first spring53 is located between the controller 14 and the second end 31 b of theUSB connector 15. For example, in attaching the inner casing 41 to theouter casing 42, the first spring 53 is resiliently bent toward thesubstrate 12 around the connection 65 between the first wall 52 and thefirst spring 53 as a fulcrum. The front end 53 b of the first spring 53then enters between the controller 14 and the second end 31 b of the USBconnector 15. Thereby, the bent first spring 53 is prevented fromcontacting and damaging the USB connector 15 and the controller 14.Further, the circumference of the first edge 25 facing the second end 31b may become a dead space with no electronic components and wirings.However, in the present embodiment, the dead space is effectively usedas a space for the first spring 53 to retract.

The first inner face 85 a can be an inclined face being further awayfrom the substrate 12 as extending to the open end 81. In this case, forexample, when attaching the inner casing 41 to the outer casing 42, theinclined first inner face 85 a presses down the protrusion 66, and thefirst spring 53 is resiliently bent toward the substrate 12. Thereby,the inner casing 41 can be easily attached to the outer casing 42.

The first end face 71 a of the first sidewall 71 is closer to the firstmounting face 21 of the substrate 12 than the first inner face 85 a andfaces the first mounting face 21. The second end face 72 a of the secondsidewall 72 is closer to the second mounting face 22 than the secondinner face 85 b and faces the second mounting face 22. Thus, the firstend face 71 a comes into contact with the first mounting face 21 torestrict the substrate 12 from moving in the direction of the firstmounting face 21 with respect to the inner casing 41. The second endface 72 a comes into contact with the second mounting face 22 torestrict the substrate 12 from moving in the direction of the secondmounting face 22 with respect to the inner casing 41. Thereby, thesubstrate 12 and the USB connector 15 are restricted from moving withrespect to the inner casing 41 in the thickness direction of thesubstrate 12.

The inner casing 41 faces the first edge 25 of the substrate 12 on whichthe USB connector 15 is mounted. This restricts the movement of thesubstrate 12 and the USB connector 15 with respect to the inner casing41 in the positive Y-axis direction. Further, the tab 68 of the secondspring 56 faces the tip end 32 a of the USB connector 15. By contactingthe tip end 32 a, the tab 68 restricts the movement of the USB connector15 with respect to the inner casing 41 in the negative Y-axis direction.Thereby, when inserting the USB connector 15 into the socket or pullingthe USB connector 15 out of the socket, the USB connector 15 can beprevented from coming off from the inner casing 41.

For example, when attaching the USB connector 15 to the socket, thesecond spring 56 is to be bent around the connection 67 between theholder 51 and the second spring 56 as a fulcrum in the direction D2 inwhich the tab 68 comes off from the tip end 32 a. However, in the Z-axispositive direction, the distance between the second spring portion 56and the second inner face 85 b is shorter than the distance between thetab 68 and the tip end 32 a opposing each other. Because of this, bycontacting with the second inner face 85 b, the second spring 56 isrestricted from bending in the direction D2. This can prevent the USBconnector 15 from coming off from the inner casing 41 without failure.

When the inner casing 41 receives a pressing force to inside the port84, the force may act on the contact between the second contact face 66b of the protrusion 66 and the second receiving face 86 b of the opening86. The force causes the first spring 53 to bend away from the firstinner face 85 a around the connection 65 between the holder 51 and thefirst spring 53 as a fulcrum. However, the protrusion 73 of the innercasing 41 is housed in the recess 87 of the outer casing 42, and thefirst side end face 73 a of the protrusion 73 faces the first internalface 87 a of the recess 87. By contacting with the first internal face87 a, the first side end face 73 a restricts the movement of the innercasing 41 with respect to the outer casing 42 in the negative Y-axisdirection. This can prevent the protrusion 66 and the opening 86 frombeing disengaged, inhibiting the inner casing 41 from coming off fromthe outer casing 42.

In the first embodiment, the inner casing 41 includes the protrusions 73and the outer casing 42 is provided with the recesses 87. However, theinner casing 41 may be provided with recesses and the outer casing 42may include protrusions in the inner periphery 85. In this case, theprotrusions are to be housed in the recesses while a part of theprotrusions facing the positive Y-axis direction (an example of thethird restrictor) and a part of the recesses facing the negative Y-axisdirection (an example of the fourth restrictor) oppose each other. Bythe contact between the protrusions and the recesses, the inner casing41 is restricted from moving with respect to the outer casing 42 in thenegative Y-axis direction. This can prevent the protrusion 66 and theopening 86 from being disengaged, inhibiting the inner casing 41 fromcoming off from the outer casing 42.

As described above, the inner casing 41 restricts the USB connector 15and the substrate 12 from moving with respect to the inner casing 41 inthe X-axis direction, in the Y-axis direction, and in the Z-axisdirection. This eliminates the necessity for the outer casing 42 to holdthe USB connector 15 and the substrate 12, improving the degree offreedom of the shape of the outer casing 42. Further, even if the designof the outer casing 42 is changed, a performance evaluation test of theinner casing 41 can be at least partially omitted, thereby curtailing anincrease in the development cost of the USB connector 15.

Second Embodiment

A second embodiment is described below with reference to FIG. 9. In thefollowing, constituent elements having same or like functions as thoseof the constituent elements described above may be denoted by the samereference numerals, and descriptions thereof may be omitted. Further,the constituent elements denoted by the same reference numerals do notnecessarily have the same functions and characteristics, and theseconstituent elements may have mutually different functions andcharacteristics according to respective embodiments.

FIG. 9 is a plan view of the USB memory 10 according to the secondembodiment, excluding the outer casing 42. As illustrated in FIG. 9, theinner casing 41 according to the second embodiment includes two firstsprings 53 and two protrusions 66.

The two first springs 53 each extend from the first wall 52 along thefirst inner face 85 a in a direction orthogonal to the positive Y-axisdirection. For example, one of the first springs 53 extends from thefirst wall 52 in the positive X-axis direction. The other of the firstsprings 53 extends from the first wall 52 in the negative X-axisdirection.

The two protrusions 66 project from the surfaces 53 a of the two firstsprings 53. The two protrusions 66 are housed in the two openings 86 inthe outer casing 42. Because of the protrusions 66 housed in theopenings 86, the first springs 53 with the protrusions 66 restrict themovement of the inner casing 41 with respect to the outer casing 42 inthe positive and negative Y-axis directions.

According to the second embodiment, when pulling out the USB connector15 of the USB memory 10 from the socket, a tensile force acts on theouter casing 42. The tensile force causes the USB connector 15 and theinner casing 41 to move in the positive Y-axis direction with respect tothe outer casing 42. However, the opening 86 comes into contact with theprotrusions 66, generating a twisting force to the first springs 53.

The twisting force causes a part of the surfaces 53 a on the positiveY-axis side to be twisted and approach the first inner face 85 a of theport 84. This presses the protrusions 66 further into the openings 86.Further, the surfaces 53 a of the first springs 53 are pressed onto thefirst inner face 85 a of the port 84. Because the first inner face 85 areceives the surfaces 53 a, deformation of the first springs 53 isprevented.

As described above, when the tensile force occurs on the inner casing41, pulling it out from the port 84, the first spring 53 bends in adirection different from the direction in which the protrusions 66 comeoff from the openings 86. This can prevent the protrusions 66 fromcoming off from the openings 86 and restrict the inner casing 41 frommoving with respect to the outer casing 42 in the positive Y-axisdirection.

For example, to pull out the USB memory 10 from the socket, a user mayapply a rotational (twisting) force around the Y-axis to the outercasing 42. In the present embodiment, because the USB memory 10 includesthe two first springs 53, one extending in the positive X-axis directionand the other extending in the negative X-axis direction, theprotrusions 66 can be prevented from coming off from the openings 86when the outer casing 42 is twisted.

In the USB memory 10 of the second embodiment described above, the firstsprings 53 extend from the first wall 52 of the inner casing 41 insidethe port 84 along the first inner face 85 a in the direction orthogonalto the positive Y-axis direction. When the inner casing 41 receives apressing force to outside the port 84, the force acts on the contactbetween the protrusions 66 and the openings 86. The force causes thefirst springs 53 to be twisted. This can prevent the protrusions 66 andthe openings 86 from being disengaged, preventing the inner casing 41from coming off from the outer casing 42.

According to at least one of the above embodiments, at least a part of aholding member that holds a USB connector is housed in a port that opensin a first direction, and a first extension provided with a protrusionextends in a direction toward an end of the holding member or in adirection orthogonal to the first direction. Thereby, the holding memberis prevented from coming off from a casing.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A USB device comprising: a USB connector; acasing provided with a port that opens in a first direction, the casinghaving a first inner face that is provided with an opening, faces adirection intersecting with the first direction, and faces the port; anda holding member including a holder, a support, and a first extension,wherein the holder is at least partially housed in the port, includes anend outside the port, and is provided with an insertion port that opensin the end, and the holder holds the USB connector while the USBconnector projects outward through the insertion port, the supportextends from the holder inside the port, the first extension includes afirst face facing the first inner face and a protrusion on the firstface, the first extension extends inside the port from the support alongthe first inner face in a direction toward the end or in a directionorthogonal to the first direction, the first extension being bendable,and the protrusion is housed in the opening.
 2. The USB device accordingto claim 1, wherein the first extension extends from the support alongthe first inner face toward the end, and the protrusion is spaced apartfrom a tip end of the first extension in an extending direction of thefirst extension.
 3. The USB device according to claim 2, furthercomprising: a substrate on which the USB connector is mounted, thesubstrate at least partially housed in the casing, including a secondface facing the first inner face and a first end facing the firstdirection; and an electronic component mounted on the second face,wherein the first extension extends from the support along the firstinner face toward the end, the USB connector has a second end opposingthe first end, and the tip end of the first extension is located betweenthe electronic component and the second end in the first direction. 4.The USB device according to claim 3, wherein the substrate has a thirdface opposite the second face, the casing includes a second inner facefacing the port and the third face, and the holding member includes afirst restrictor and a second restrictor, the first restrictor beingcloser to the second face than the first inner face and facing thesecond face, the second restrictor being closer to the third face thanthe second inner face and facing the third face.
 5. The USB deviceaccording to claim 4, wherein the holding member further includes asecond extension extending from the holder, and faces the first end ofthe substrate, the USB connector includes a third end in a seconddirection opposite to the first direction, the third end is locatedinside the port, and the second extension includes a tab facing thethird end.
 6. The USB device according to claim 5, wherein the secondinner face faces the second extension, and a distance between the secondextension and the second inner face is shorter than a distance betweenthe tab and the third end in a direction where the second inner facefaces.
 7. The USB device according to claim 6, wherein the casingincludes an inner periphery including the first inner face and facingthe port, the inner periphery is provided with one of a protrusion and arecess, the holding member is provided with the other of the protrusionand the recess, the protrusion is housed in the recess, the one of theprotrusion and the recess includes a third restrictor facing the firstdirection, and the other of the protrusion and the recess includes afourth restrictor facing the second direction and facing the thirdrestrictor.
 8. The USB device according to claim 5, wherein the casingincludes an inner periphery including the first inner face and facingthe port, the inner periphery is provided with one of a protrusion and arecess, the holding member is provided with the other of the protrusionand the recess, the protrusion is housed in the recess, the one of theprotrusion and the recess includes a third restrictor facing the firstdirection, and the other of the protrusion and the recess includes afourth restrictor facing the second direction and facing the thirdrestrictor.
 9. The USB device according to claim 2, wherein in anextending direction of the first extension, the protrusion is furtheraway from a connection between the protrusion and the support than froma tip end of the first extension.
 10. The USB device according to claim1, further comprising: a substrate on which the USB connector ismounted, the substrate at least partially housed in the casing,including a second face facing the first inner face and a first endfacing the first direction; and an electronic component mounted on thesecond face, wherein the first extension extends from the support alongthe first inner face toward the end, the USB connector has a second endopposing the first end, and a tip end of the first extension is locatedbetween the electronic component and the second end in the firstdirection.
 11. The USB device according to claim 10, wherein thesubstrate has a third face opposite the second face, the casing includesa second inner face facing the port and the third face, and the holdingmember includes a first restrictor and a second restrictor, the firstrestrictor being closer to the second face than the first inner face andfacing the second face, the second restrictor being closer to the thirdface than the second inner face and facing the third face.
 12. The USBdevice according to claim 11, wherein the holding member furtherincludes a second extension extending from the holder, and faces thefirst end of the substrate, the USB connector includes a third end in asecond direction opposite to the first direction, the third end islocated inside the port, and the second extension includes a tab facingthe third end.
 13. The USB device according to claim 12, wherein thesecond inner face faces the second extension, and a distance between thesecond extension and the second inner face is shorter than a distancebetween the tab and the third end in a direction where the second innerface faces.
 14. The USB device according to claim 13, wherein the casingincludes an inner periphery including the first inner face and facingthe port, the inner periphery is provided with one of a protrusion and arecess, the holding member is provided with the other of the protrusionand the recess, the protrusion is housed in the recess, the one of theprotrusion and the recess includes a third restrictor facing the firstdirection, and the other of the protrusion and the recess includes afourth restrictor facing the second direction and facing the thirdrestrictor.
 15. The USB device according to claim 12, wherein the casingincludes an inner periphery including the first inner face and facingthe port, the inner periphery is provided with one of a protrusion and arecess, the holding member is provided with the other of the protrusionand the recess, the protrusion is housed in the recess, the one of theprotrusion and the recess includes a third restrictor facing the firstdirection, and the other of the protrusion and the recess includes afourth restrictor facing the second direction and facing the thirdrestrictor.
 16. The USB device according to claim 10, wherein thesubstrate includes a third face opposite the second face, and the USBconnector is mounted on the third face.
 17. The USB device according toclaim 10, further comprising a flash memory mounted on the substrate,wherein the electronic component includes a controller that controls theflash memory.
 18. The USB device according to claim 1, wherein a depthof the opening is longer than a length of the protrusion in a projectingdirection of the protrusion.
 19. The USB device according to claim 1,wherein the holder includes an outer periphery facing outside of theholder, a depression is provided in a part of the outer peripheryoutside the port, the depression into which a tab of a lid that coversthe USB connector is fitted.
 20. The USB device according to claim 1,wherein the first extension includes two first extensions, and the twofirst extensions extend from the support in a direction orthogonal tothe first direction and oppositely to each other.